Mental toughness is not a track that some posses while others do not. It can be developed by anyone regardless of who the person may be. Jeff Haden lists out nine things that mentally tough people do.
Apply these tips so that your mental toughness (and maybe your success) will develop. One of the tips is to put aside the things that you have no ability to impact:
Mental strength is like muscle strength--no one has an unlimited supply. So why waste your power on things you can't control?
For some people, it's politics. For others, it's family. For others, it's global warming. Whatever it is, you care, and you want others to care.
Fine. Do what you can do: Vote. Lend a listening ear. Recycle, and reduce your carbon footprint. Do what you can do. Be your own change--but don't try to make everyone else change.